1. TECHNICAL FIELD
The present invention is directed toward window operators, and more particularly toward window operators wherein the operating mechanism is supported directly by the cover and the base. The present invention is also directed toward window operators having reduced air/water infiltration.
2. BACKGROUND ART
Windows are commonly constructed having a frame and a sash. The sash is pivotally secured to the frame for motion between a closed position, wherein the sash fits substantially within the frame, and an open position, wherein the sash is rotated relative to the frame so that the sash is not substantially within the frame.
Window operators used to control the movement of the sash between the open and closed positions are well known in the art. A window operator typically has a mounting base with a flat planar bottom secured to a corresponding flat planar surface on a sill of the frame. The mounting base rotatably mounts a gear or gear train and an arm. The gear or gear train meshes with a worm on a worm shaft having either a manually operated handle or motorized controller attached thereto. The arm is operatively connected to the sash of the window whereby rotation of the worm shaft results in rotation of the gear or gear train and the arm for movement of the window between the open and closed positions. Examples of typical manually operated window operators can be found in U.S. Pat. Nos. 4,253,276, 4,266,371, 4,445,794 and 4,845,830.
As illustrated in greater detail in U.S. Pat. Nos. 4,445,794 and 4,845,830, window operators are typically manufactured with the worm mounted in an upwardly angled generally tubular housing integrally formed in the base. Through an aperture in the housing, the worm meshes with the gear or, alternatively, the gear train. The gear is operably associated with the arm such that rotation of the worm results in rotation of the gear and associated arm about a fixed pivot pin.
To secure the worm in place in the tubular housing, a retainer bearing is threaded into position at an open end of the housing. The threaded retainer bearing, as shown in U.S. Pat. No. 4,253,276, may be held in place by use of an additional structural element, such as a locking pin, wedged between the threads of the bearing and the housing. Use of the locking pin may be avoided through the use of a specially shaped retainer bearing and limited deformation of the housing, such as shown in U.S. Pat. No. 4,505,601. Yet another alternative locking arrangement is shown in U.S. Pat. No. 4,445,794, wherein the retainer bearing locks the worm in place by stripping the threads at the open end of the housing as the retainer bearing is advanced into the housing
To install the assembled operator to the window, the flat planar bottom surface of the operator is placed against the flat planar bottom surface of a window frame sill. A gasket may be placed around the rear of the operator and between the operator and the sill. The base is then secured against the sill through the use of fasteners, such as screws, disposed through apertures in the base.
The above window operators are hard to make, and are consequently expensive to make. Cores or paddles must be used to shape the tubular housing.
Moreover, additional manufacturing steps must be performed and additional costs must be incurred because a separate, threaded retainer bearing is required to hold the worm in the tubular housing. Use of a separate retainer bearing increases the part count and the complexity of the assembly process. Furthermore, because a threaded retainer bearing is commonly used, additional preparatory machining steps must be performed on the tubular housing prior to assembly. Costs may be increased even further if an advanced locking mechanism, such as that shown in U.S. Pat. No. 4,505,601, is used because of the sophistication of the retainer bearing used and the assembly steps required.
Additionally, by securing the arm to the base using a simple pin, the operator is sensitive to variations in the tolerance of the constituent pieces and in the manufacturing processes. Therefore, in order to control the sensitivity of the device, as expressed in the gear arm backlash, tolerances and processes must be kept within narrowly defined limits. By restricting the range of allowable tolerances and processes, however, the cost per operator is necessarily increased.
Furthermore, the design of the above operators allows for air and water to infiltrate through the operator. Use of a retainer bearing normally prevents the operator from being assembled with a seal which acts to prevent substantial air flow through the worm housing opening. Additionally, air and/or water may infiltrate around the rear of the operator and between the bottom of the base and the flat planar surface of the window frame sill.
Attempts have been made in the industry to address some of these problems. For example, an operator has been designed which uses a conventional tubular worm housing, similar to that shown in U.S. Pat. No. 4,266,371, but in combination with an arm which is secured between mating interior surfaces of the cover and the base. In particular, a central post depends from an interior surface of the cover through an aperture in the base. The arm having a gear and a bearing associated therewith is pivotally mounted on the central post. The arm is secured in place by passing the central post through the aperture, and then riveting the post in place.
Additionally, this operator has a rearwardly protruding edge integral with the base disposed around the rearwardly facing surface of the base. A gasket may be placed around the rearwardly protruding edge to limit the infiltration of water and air around the operator.
However, this operator still presents all of the problems outlined above when a conventional worm housing integral with the base is used. Additionally, this operator fails to address the problem of infiltration of air and/or water at the base/sill interface.
The present invention is directed toward overcoming one or more of the problems discussed above.
In one aspect of the invention, an operator for controlling the movement of a window sash relative to a frame between open and closed positions includes a base attachable to the frame and having a first support surface, and a cover secured to the base and having a second support surface with a hole therethrough defining an internal shoulder, the second support surface mating with the first support surface. An arm is pivotally secured to the base and attachable to the sash to control the movement of the sash between open and closed positions. A worm drivably engages the arm. The worm has a worm shaft and a worm shoulder disposed on the worm shaft. The worm is directly supported by the first and second surfaces at one end and the worm shoulder engages the internal shoulder as the worm shaft protruding from the hole.
In another aspect of the invention, an operator for controlling the movement of a window sash relative to a frame between open and closed positions comprises a base attachable to the frame and having a first support surface and an aperture, and a cover secured to the base and having a second support surface with a hole therethrough defining an internal shoulder, the second support surface mating with the first support surface. A post extends from the cover and through the aperture. An arm is pivotally secured to the post and attachable to the sash to control the movement of the sash between open and closed positions. A worm drivably engages the arm and includes a worm shaft and a worm shoulder disposed on the worm shaft. The worm is directly supported by the first and second surfaces at one end and the worm shoulder engages the internal shoulder with the worm shaft protruding from the hole.
In an additional aspect of the invention, a method of manufacturing a window operator is provided wherein the operator includes a base attachable to a frame and having a first support surface and a plurality of apertures, a cover secured to the base and having a second support surface with a hole therethrough defining an internal shoulder, the second support surface mating with the first support surface, a central post and a plurality of fastener posts extending from the cover and through the plurality of apertures, an arm pivotally secured to the central post and attachable to a sash to control the movement of a sash between open and closed positions, and a worm drivably engaging said arm and having a worm shaft and a worm shoulder disposed on the worm shaft, said worm directly supported by the first and second surfaces at one end and the worm shoulder engaging the internal shoulder with the worm shaft protruding from the hole. The method includes the steps of passing the worm shaft through the hole with the worm shoulder engaging the internal shoulder and the worm disposed against the first support surface, fitting the arm to the central post, the arm in drivable engagement with the worm, placing the base and the cover together with the worm disposed between the first and second support surfaces and the central post and plurality of fastener posts protruding through the plurality of apertures, forming the central post, controlling the time and force applied in said central post forming step to eliminate the axial play along the central post, and securing said plurality of fastener posts.
In a further aspect of the invention, an operator for use with a window having a frame with a raised surface protruding from a frame sill and a sash moveable relative to the frame between open and closed positions includes a base having an interior support surface and a bottom exterior surface with a slot therein, the base attached to the frame with the raised surface fitting substantially within the slot. An arm is pivotally secured to the base and attachable to the sash to control the movement of the sash between open and closed positions. A worm is disposed within the interior support surface and drivably engages the arm.
In another aspect of the invention, an operator for use with a window having a frame with a raised surface protruding from a frame sill and a sash moveable relative to the frame between open and closed positions includes a base having a first support surface and a bottom exterior surface with a slot therein, the base attached to the frame with the raised surface fitting substantially within the slot, and a cover secured to the base and having a second support surface with a hole therethrough defining an internal shoulder, the second support surface mating with the first support surface. An arm is pivotally secured to the base and attachable to the sash to control the movement of the sash between open and closed positions. A worm drivably engages the arm and has a worm shaft and a worm shoulder disposed on the worm shaft. The worm is directly supported by the first and second surfaces at one end and the worm shoulder engages the internal shoulder with the worm shaft protruding from the hole.
It is an object of the invention to provide a window operator using parts which are easier and less expensive to manufacture and assemble.
It is a further object of the invention to provide a window operator which is less sensitive to tolerance or assembly process variations.
It is also an object of the invention to provide a window operator which prevents substantial air and water infiltration therethrough.
It is additionally an object of the invention to provide a window operator system with a complete sealing surface at the system/window interface which prevents substantial air and water infiltration therethrough.